Colour plays an important part in our lives and particularly in our food. Without colour additives most biscuits would look the same pale brown. The yellow or orange colour of eggs and butter are carried through in cakes and pastry and in many cases an artificial colour is added to biscuit dough to suggest richness due to these ingredients even when neither has been used. Sandwich creams or jellies with fruit flavours seem much more authentic and palatable when coloured appropriately than if they are white or colourless.

In the early days of the food industry a few natural colours were used to enhance products. These include cochineal (red), an extract from the bodies of certain insects, saffron (yellow) from the stigmas of a crocus flower and, of course, caramel (brown) from burnt sugar. The development of the chemistry of aniline, or coal tar, dyes presented the industry with a whole range of intense stable colours which performed very well in foods. In combination, practically any colour could be achieved from very small amounts of dye and at low cost.

Toxicological and allergy tests indicate that some of these dyes should not be used, especially where they are heated as in the baked parts of foods. Consumer reaction has been so strong that in some countries no colouring, especially artificial colouring, of foods is allowed and always there is need or a request for clear labelling of which colours have been used.

Plant pigments such as carotenoids, xanthophylls, anthocyanins, and betalines which are responsible for the familiar colours of chlorophyll, fruit skins and beetroot colours have been extracted, concentrated and can be used as "natural" food colours. Whether they are really less harmful to health or not does not seem to have been disputed but they have disadvantages because they are often less stable to heat, pH and light and the range and depth of colouration is not so good as the aniline dyes.

Variations in national legislation on food colours probably gives more problems for exporters than any other factor. It is, therefore, felt likely to be misleading to give any sort of particular account of various colouring materials since checks must always be made to establish the current legislative position in each country.

Brown, red and even black colouration of biscuit doughs can be achieved by using cocoa powders. Cocoas which have been "dutched" with alkaline to varying degrees give dark colours, but not necessarily good flavours. The black dough of the famous Oreo biscuit shell is coloured with cocoa.

Black colouration can be given by inclusion of charcoal. Charcoal used to be used in considerable quantities in biscuits designed to aid digestion because of the ability of charcoal to absorb unwanted stomach acids etc.